well, since there are so many questions about reactor i figured i would try and pass along my hints for reactor. although many people will know HOW to do this, they may have not thought of it.
Want quick and easy cloth? a great way to have a still cloth made (relativly) quickly is to create a reactor setup with your cloth and objects that you want it to interact with. you can then create the animation and choose a key where the cloth looks best to you. use the snapshot too (tools >> snapshot) and voilia! instant cloth. if you didn’t use a lot of iternations for the plane then you can smooth the cloth a bit and it will look better. remember, the more iternations the more accurate.
things suddenly exploding? lower your colision tolerance (utilities >> reactor >> world) and things won’t explode. i reccomend .3
objects passing though each other? raise your substeps (utilities >> reactor >> preview and animation >> substeps/key). this will increase the amount of calculations max has to do and therefore there is less likely for an object to go past the collission detection between substeps and pass through the object.
after you assign a cloth (or rope) vertex to a rigid body, do you get a message saying no vertex assigned and ignoring constraint? this is kinda funky but ive noticed there is a definite series of steps to do to get this to work.
a. select the vertex
b. create the constraint (its near the bottem of the cloth modifier) with vertex STILL SELECTED
c. choose the constraint and then pick the rigid body (VERTEX STILL SELECTED)
d. preview (VERTEX STILL SELECTED)
e. hopefully it all worked, and you should be able to deselect now. if you watned to do another vertex to another rigid body (this DOES work, ive done it) then you repeat the process. if… you happen to lose the first one that you made (or the constraint gets switched to the new vertex) delete the old constraint which had the rigid body nothing is attached too anymore, and repeat the steps.
its kinda fiddly so it sometimes takes multiple trys for it to work.
for pretty much any object more complicated than a primative (ie: got holes, grooves which you want rector to see, etc) your probably going to have to make the rigid body a concave mesh (property editor >> concave). to be sure… you can test its convexity! (reactor >> utiliites >> convexity test)
rope object streching a lot? you can make it so that it keeps its shape (hit constraint, its the other option instead of spring) if an object is attached to it the rope may still strech, so increase the mass of the rope from 1 and it should deal with the stretching.
cloth/rope object? going through itself. in their respective modifiers hit “avoid self intersections” and it should help with this. if its still not doing what you want you can increase the various stiffness, fold stiffness, etc of the objects so that they can’t phyiscally reach that point of self-intersectons.
hope this sorta helped, any other people with hints are certainly welcome.